There are two places that I go for phone comparison data:
PhoneArena
It is fairly simple to setup the comparison – and the review ratings are often bang on.
GSMArena goes tellingly further, offering just great camera comparisons like the following:
Note the camera comparison is truly robust – click on the Gray Chart tab on the bottom of the image and a new image is brought up for further side by side comparison. Ditto for the Color Poster tab. Note the green rectangle in the middle of the image. That is movable with the mouse – just click and drag for more comparative views of the image. Finally the drop down widgets allow users to change the selected smartphones very easily. Note that the site has video and camera spec comparison pages as well.
If you have a favorite place to do your smartphone comparison shopping, please add it to the comments below.